The invention relates to an apparatus for recording a digital information signal in a track on a record carrier, the apparatus including:
input apparatus for receiving the digital information signal;
encoding apparatus for encoding the digital information signal so as to obtain a channel signal, the encoding apparatus including a nT precoder, where n is an integer for which holds n.gtoreq.1, and T is the bit time in the digital information signal, the nT precoder including signal combination apparatus and delay apparatus for realizing a signal delay of nT;
preamble signal generating apparatus for generating a preamble signal;
switching apparatus for combining the preamble signal and the channel signal, the switching apparatus having a first and second input, an output and a control signal input, the first input of the switching apparatus being coupled to an output of the preamble signal generating apparatus;
timing apparatus for timing the switching apparatus such that the switching apparatus supplies a channel encoded block of information of the digital information signal which is preceded by the preamble signal;
writing apparatus for writing the preamble signal and the channel encoded block of information of the digital information signal in the track on the record carrier, and to encoding apparatus for encoding said digital information signal.
An apparatus as defined in the opening paragraph is known from EP-A 492,704, to which U.S. Pat. No. 5,245,493 corresponds, see especially the FIG. 12. n equals 2 in the prior art apparatus.
The prior art apparatus records a digital information signal, that may be a digital video signal or a digital audio signal or may include both the digital video signal and the digital audio signal or may even include a digital data signal, in slant tracks on a record carrier. The tracks are formed by a preamble track portion in which a preamble signal is recorded, followed by a data track portion in which the channel signal is recorded. The channel signal recorded in a data track portion is the 2T precoded version of a sequence of datablocks (syncblocks) each datablock (syncblock) including a sync word which is followed by a number of bytes of information. The preamble signal is used during reproduction to lock the internal oscillator of the reproducing apparatus to the bitclock included in the preamble signal. Next, the syncwords in the datablocks (syncblocks) are detected so as to enable the retrieval of the data information included in the data blocks.
Those skilled in the art are also directed to EP-A 317,013 to which U.S. Pat. No. 5,128,811 corresponds.
The above citations are hereby incorporated in whole by reference.